ogrpoint.cpp

mitab,读取MapInfo的地图文件

/******************************************************************************
 * $Id: ogrpoint.cpp 10646 2007-01-18 02:38:10Z warmerdam $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The Point geometry class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999, Frank Warmerdam
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "ogr_geometry.h"
#include "ogr_p.h"
#include <assert.h>

CPL_CVSID("$Id: ogrpoint.cpp 10646 2007-01-18 02:38:10Z warmerdam $");

/************************************************************************/
/*                              OGRPoint()                              */
/************************************************************************/

/**
 * Create a (0,0) point.
 */

OGRPoint::OGRPoint()

{
    x = 0;
    y = 0;
    z = 0;
}

/************************************************************************/
/*                              OGRPoint()                              */
/*                                                                      */
/*      Initialize point to value.                                      */
/************************************************************************/

OGRPoint::OGRPoint( double xIn, double yIn, double zIn )

{
    x = xIn;
    y = yIn;
    z = zIn;
    nCoordDimension = 3;
}

/************************************************************************/
/*                              OGRPoint()                              */
/*                                                                      */
/*      Initialize point to value.                                      */
/************************************************************************/

OGRPoint::OGRPoint( double xIn, double yIn )

{
    x = xIn;
    y = yIn;
    z = 0.0;
    nCoordDimension = 2;
}

/************************************************************************/
/*                             ~OGRPoint()                              */
/************************************************************************/

OGRPoint::~OGRPoint()

{
}

/************************************************************************/
/*                               clone()                                */
/*                                                                      */
/*      Make a new object that is a copy of this object.                */
/************************************************************************/

OGRGeometry *OGRPoint::clone() const

{
    OGRPoint    *poNewPoint = new OGRPoint( x, y, z );

    poNewPoint->assignSpatialReference( getSpatialReference() );
    poNewPoint->setCoordinateDimension( nCoordDimension );

    return poNewPoint;
}

/************************************************************************/
/*                               empty()                                */
/************************************************************************/
void OGRPoint::empty()

{
    x = y = z = 0.0;
}

/************************************************************************/
/*                            getDimension()                            */
/************************************************************************/

int OGRPoint::getDimension() const

{
    return 0;
}

/************************************************************************/
/*                          getGeometryType()                           */
/************************************************************************/

OGRwkbGeometryType OGRPoint::getGeometryType() const

{
    if( nCoordDimension < 3 )
        return wkbPoint;
    else
        return wkbPoint25D;
}

/************************************************************************/
/*                          getGeometryName()                           */
/************************************************************************/

const char * OGRPoint::getGeometryName() const

{
    return "POINT";
}

/************************************************************************/
/*                            flattenTo2D()                             */
/************************************************************************/

void OGRPoint::flattenTo2D()

{
    z = 0;
    nCoordDimension = 2;
}

/************************************************************************/
/*                       setCoordinateDimension()                       */
/************************************************************************/

void OGRPoint::setCoordinateDimension( int nNewDimension )

{
    nCoordDimension = nNewDimension;
    
    if( nCoordDimension == 2 )
        z = 0;
}

/************************************************************************/
/*                              WkbSize()                               */
/*                                                                      */
/*      Return the size of this object in well known binary             */
/*      representation including the byte order, and type information.  */
/************************************************************************/

int OGRPoint::WkbSize() const

{
    if( nCoordDimension != 3 )
        return 21;
    else
        return 29;
}

/************************************************************************/
/*                           importFromWkb()                            */
/*                                                                      */
/*      Initialize from serialized stream in well known binary          */
/*      format.                                                         */
/************************************************************************/

OGRErr OGRPoint::importFromWkb( unsigned char * pabyData,
                                int nSize )

{
    OGRwkbByteOrder     eByteOrder;
    
    if( nSize < 21 && nSize != -1 )
        return OGRERR_NOT_ENOUGH_DATA;

/* -------------------------------------------------------------------- */
/*      Get the byte order byte.                                        */
/* -------------------------------------------------------------------- */
    eByteOrder = DB2_V72_FIX_BYTE_ORDER((OGRwkbByteOrder) *pabyData);
    assert( eByteOrder == wkbXDR || eByteOrder == wkbNDR );

/* -------------------------------------------------------------------- */
/*      Get the geometry feature type.  For now we assume that          */
/*      geometry type is between 0 and 255 so we only have to fetch     */
/*      one byte.                                                       */
/* -------------------------------------------------------------------- */
    OGRwkbGeometryType eGeometryType;
    int                bIs3D;
    
    if( eByteOrder == wkbNDR )
    {
        eGeometryType = (OGRwkbGeometryType) pabyData[1];
        bIs3D = pabyData[4] & 0x80 || pabyData[2] & 0x80;
    }
    else
    {
        eGeometryType = (OGRwkbGeometryType) pabyData[4];
        bIs3D = pabyData[1] & 0x80 || pabyData[3] & 0x80;
    }

    assert( eGeometryType == wkbPoint );

/* -------------------------------------------------------------------- */
/*      Get the vertex.                                                 */
/* -------------------------------------------------------------------- */
    memcpy( &x, pabyData + 5, 16 );
    
    if( OGR_SWAP( eByteOrder ) )
    {
        CPL_SWAPDOUBLE( &x );
        CPL_SWAPDOUBLE( &y );
    }

    if( bIs3D )
    {
        memcpy( &z, pabyData + 5 + 16, 8 );
        if( OGR_SWAP( eByteOrder ) )
        {
            CPL_SWAPDOUBLE( &z );
        }
        nCoordDimension = 3;
    }
    else
    {
        z = 0;
        nCoordDimension = 2;
    }

    return OGRERR_NONE;
}

/************************************************************************/
/*                            exportToWkb()                             */
/*                                                                      */
/*      Build a well known binary representation of this object.        */